1. Field of the Invention
The present invention relates to processes for producing butter/margarine products.
2. Description of the Prior Art
Blended butter/margarine products are quite old. The Hodds U.S. Pat. No. 263,042 issued on Aug. 22, 1882 describes a process wherein a fraction of vegetable oil is subjected to pressure and temperature making the vegetable oil compatible with an "animal oleo margarine." Both the "animal oleo margarine" and the vegetable oil are melted and mixed with cream before emulsionizing. The mixture is then churned to obtain the "artificial butter" of the Hodds patent.
The Howe U.S. Pat. No. 2,357,896, also describes a process in which a butter/margarine blend is produced by simply mixing the butter and the vegetable oil in a molten state.
A further refinement in the production of a butter/margarine blend included the addition of the vegetable oil to the cream during the churning process. The addition of the oil during the churning step is discussed in the Lauferty U.S. Pat. Nos. 264,714 and 265,833 and the Wall U.S. Pat. No. 1,386,475. In both Lauferty patents, the oleo margarine is added to the cream after the cream has been churned for approximately five minutes. In addition, in the Lauferty U.S. Pat. No. 264,714, the oleo margarine was agitated in a tank prior to addition to the cream to break up the globular formations in the oil. In the Wall patent, cocao oil is added to the cream at the point of incipient butter formation.
Other prior art patents, namely the Cochran U.S. Pat. No. 285,878, the Libreich U.S. Pat. No. 611,495, the Winship et al U.S. Pat. No. 1,028,804 and the Vahlteich U.S. Pat. No. 2,485,634, describe processes wherein the vegetable oil is mixed with the cream or milk prior to churning.
Still other processes are described in other patents wherein the vegetable oil/milk mixture is passed through a homogenizer or is emulsified. In the Ashby U.S. Pat. No. 1,400,341, an 80% vegetable oil and 20% milk mixture is passed through an emulsifying machine at approximately 68.degree. prior to churning. In the Forman et al U.S. Pat. No. 4,177,293, a lowfat content butter/spread is produced by starting with cream which can include a vegetable oil, innoculating the mixture and then homogenizing. After homogenization, fermentation is permitted and then the mixture is homogenized a second time. The product of the Forman et al process is then directly packaged.
However, with the exception of the previously mentioned Lauferty U.S. Pat. No. 264,714, all of the processes described in the above-mentioned patents show little concern for globule size within the oil and the cream. The Johansson U.S. Pat. No. 4,209,546 teaches that vegetable oil when introduced into a cream stream of a butter/margarine blend process needs to be gently and carefully added to the cream stream so that the fat globules of the cream and the oil respectively, will not be broken up into minute fat globules. The minute fat globules decrease churning efficiency of the churning process since the globules do not participate in the formation of edible fat, but instead are taken out with buttermilk which is a byproduct of the churning process.
Churning efficiency has not been emphasized in the majority of the processes described in the above-mentioned patents in the production of butter/margarine blends. Typically, butter/margarine blends are churned using the same churning processes as are used to churn butter. With increased labor and operating costs, increasing the efficiency of the churning process to handle butter/margarine blends would be of a great advantage.